Anchoring device



E. A. M. BANDOLY.

ANCHORING DEVICE.

APPLICATION FILED OCT- 4. 1920.

1,373,645. I I Patented Apr. 5, 1921.

- narrates.

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UH'EBD EBIGH M.

on overseen, iterators.

DIEWMWL m max-rum application filed tictcber 4,1921). Serial No. Ml-shift.

, vices; and I do hereby declare the following to be afull, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make! and use the same.

, ,My invention relates to fastening devices I suitable for use in someof the compressible materials, such as wood, its general objects beingto means for automatically anchoringan object inserted in a here, sothat the inserted object will be able to resist the strains tending towithdraw it. More particularly, my invention relates to nuts suitablefor use in connection with machine screws or bolts as substitutesfor-wood screws in affording permanently secure fastenings. In thisaspect my invention aims to provide a nut adapted to be driven into abore in the wood and so equipped that theinserted nut will be socurelylocked against rotation, that it will offer a decided resistance to thescrew or bolt tending to withdraw itirom the bore, and

that it will automatically lock itself against withdrawal after arelatively short outward movement due to such a strain.

In constructing phonograph cabinets, piano cases, ofiice furniture andthe like,

much trouble has heretofore been experienced owing to the loosening ofthe -wood screws used for fastening the various parts to one another.This difliculty has been all the more serious where the demands of hastehave not allowed ample time for the proper drying of the wood, as hasbeen true owing to business conditions brought about by the recent war.Consequently, muchdissatis" faction has resulted from 3 the loosening ofwood screws due to the"gradual,shrinking of the wood on objects inwhichthese screws were originally quite firmly tightened, and

hea losses have been encountered owing to t e rejection and return ofthe goods, which proved defective on t is account. Likewise, if eitherthe manufacturer orthe purchaser attem ted an adequate tightening of thescrews,th1 s has sometimes resulted in a stripping of the thread in thewood and a consequent damaging of the object.

Moreover, the relatively li pitch of wood screws-always makes it easy'for them to Specification of Letters Patent.

provide simple and inexpensive a ing nut Patented Apr 5 work loose ascompared. withthe similar pitch of machine screws of correspondingdiameter, so that for really permanent fastenings, the machine screwsafford decided advantages. a Y

My invention aims to provide means whereby these advantages of themachine screw thread may be employed when male ing fastenings in wood,more particularly aims to provide can easily be embodiedin the wood anddrive nut which which wiil effectively anchor itself so as to V afford afirm operative connection between the wood and a screw or bolt having aregu lar machine screw thread. Still i'urther and more detailed objectswill appear from the following specification'and fromthe accompanyingdrawings, in which drawings- Figure 1- is an elevation of aself-anchorsigned for insertion in abore' corresponding in diameter tothe diameterof the tapering capof the nut. v x

Hg. 2 1s a fragmentary central and lon gitudinal section through thesame nut and through the tail end of a machine screw or bolt associatedtherewith showingthis nut as it appears after it has a bore in a boardand before it has been subjected through the screw or bolt to a straintending to withdraw the nutfrom the bore.

Fig. 3' 1s a similar section, showing the manner in which the same nutanchors itself in the wood when the screw or bolt associated therewithhas moved the nut for a relatively short distance in attempting towithdraw the nut from the bore.

'Fig. i is a transverse section through the self-anchoring nut of Figs.1 to 3 inclusive,

embodying my invention and debeen driven into taken along thecorrespondingly numbered a line in Fig. 1. p

Fig. 5 is an elevation of another embodiment, namely aself-anchoring nuthaving a plain cylindrical tail piece and having both its shank and itsanchoring collar hexagonal incross-section.

Fig. 6 is a transverse section through the embodiment of Fig. 5,taken'along the correspondingly num' cred line in that figure.

In the embodiment of the first three figures of the drawings, of myinvention comprises a metal cap nut having a tapering tip 1 connected toa rear end portion 2 by a shank 3 of a diameter somewhat smaller thanthat of the parts 1 and 2. 'llhecap 1 is desirably of a diameter thefastening device so that these'ribs will then prevent the nut frombeing'rotatedin the bore.

Surrounding the medial shank 3 of the nut is a collar 4 which isdesirably formed of spring metal and which has a series of prongs 5formed from it intermediate of its ends.- These tongues all extendtoward the tailportion2 of the nut and initially are sprung slightlyoutward from the axis of the collar so that the tip or free end of eachtongue initially projects for a distance somewhat greater from the axisof the collar than the radius of the bore in which the resultingfastening device is to be inserted. Conse quently, when the device(consisting of the said nut and collar) is driven into the bore, theresiliency of the tongues will force their, tips to engage the wall ofthe bore, and a retractile movement of the collar will therefore causethese tips to indent themselves into the wood." To augment this action,I

provide the cap 1 with a square shoulder at its juncture with the shank3, so that the forward end of the collar will engage this shoulder, andI also desirably form the said tongues so that their tips will beacuteangled and therefore more re'adyto dig into the "wood. I alsodesirably arrange the tongues 5 in a pair of rows extendingcircumferentially of the collar and with the tongues in successive rowsin staggered relation to each ,other,-whereby I increase the number ofpoints at which the collar is engaged with the wood without unduly weaksuing the collar.

In practice, I have found such. a fastening device to be particularlysuitable for use in connection with machine screws as substi 'tute's forthe wood screws heretofore used in assembling parts of automobiles,phonograph cabinets and various items of furniture. For such purposes,the bore in the wood is desirably made a little in excess of the depthrequired for the nut, and my fastening device is driven into this boreuntil its rear on has entered the bore for some distance behind themouth of the latter. The resulting space between the extreme rear end ofthe nut and the surface of the wood then allows for a partial retractingof the nut by the'initial pull of the screw or bolt 7 which is threadedinto this nut. .That is to say, when the strain is placed on this screw,the hurling on the rear portion 2 prevents the latter from turning withthe screw or bolt, so that the nut slides lightly backward toward themouth of the hole without rotating. During this sliding move naraeeament of the nut, the engagementot the for Ward end of the collar 4 withthe adjacent shoulder on the head 1 moves the collar backward also,thereby causing the tongues 5 to dig into the wood and gradually to turnoutward at an increased angle withthe axis of the nut, after the mannershown in Fig.

wood screws, I can obtain a security offastoning farin excess of thataiiorded by the latter. I

However, while I have heretofore de scribed my invention in a highlydesirable embodiment, I do not wish to be limited to the details ofconstruction and arrange ment thus disclosed, it being obvious thatvarious additions, omissions or other changes might be made withoutdeparting from the spirit of my invention. For .,.example, the nurlingof the tail portion may not be ample to prevent a rotating of the nutwhen the same is made for large sizes of screws or bolts. For theselarger forms, I may employ a smooth cylindrical tail 8 as shown in Fig.5 and may employ a shank 9 of hexagonal cross-section and I'may use acollar 10 of correspondingly angular cross-section. Thus arranged, theforcible engagement of the tips of the tongues with the wood willprevent the collar from rotating, and the interlocking of the angularlysectioned collar with the shank of the nut will prevent the latter fromrotating within the collar, hence the tongues 'will simultaneouslyanchor the nut both against retraction and against rotation.

I claim as my invention: 1. A self-anchoring nut or the like comprisinga main member equipped intermediate its ends with a peripheral groove,and a collar seated. in the said groove and having outwardly projectingtongues formed there from and all extending in the same direction.longitudinally of the collar.

2. A self-anchoring nut or the like COHL' prising a main member having apair oft ends of substantially equal diameter connected by a shank ofrelatively smaller diameter, one of the. said ends having formationsdirected radially outward therefrom; and a collar of resilient materialsurrounding the said shank and equipped with tongues all extendingtoward one of the said ends and all having their tips normally forcedoutward by the resiliency 01" the tongues beyond the periphery of thecollar.

Ital

ltiil ill/ii i. lit:

3. A self-anchoring nut or the like comprising a main member equippedintermediate its ends with a peripheral groove, and a collar seated inthe said groove and having outwardl projecting tongues formed therefromand all extending toward the tail end thereof; the main member having alongitudinally fluted tail end of larger effective diameter than themain portion of the collar, whereby the flutes thereof are adapted toindent themselves in the walls of the bore slidably entered by the mainportion of the collar so as to lock the main member against rotation.

4;. A self-anchoring nut comprising a peripherally grooved main memberslidably fitting the bore into which the nut is to be inserted, and acollar disposed in the said peripheral groove and having resilienttonguesyieldingly e a in the said bore the collar being form il gf gsin1e piece of sheet material wrapped around t egrooved part ofthe said"main member and the tonglies being. integral with the collar.

5; or anchoring a peripherally ooved nut in a bore completely housing te said nut, a collar disposed in thesaid groove and having resilienttonguesieldingly engaging the said bore and al directed toward themoutli of the bore, disposed in a plurality of rows extendingcircumferentially of thecollar and with the tongues in adjacent rows inrelatively staggered relatio Signed at Chicago, Illinois, September30th; 1920. r

ERIGH A.- 1x4 BANDOLY.

the tongues being

